Blowout preventer and ram therefor



2, 1960 H. ALLEN 2,947,508

BLOWOUT PREVENTER AND RAM THEREFOR Filed April 6, 1956 2 Sheets-Sheet 1Herbert /4//en IN VENTOR.

Aug. 2, 1960 H. ALLEN 2,947 5 BLOWOUT PREVENTER AND RAM THEREFOR FiledApril 6, 1956 2 Sheets-Sheet 2 f/e/ue/ I /4//en INVENTOR.

BLOWOUT PREVENTER AND RAM THEREFOR Herbert Allen, Houston, Tex.,assignor to Cameron Iron Works, Inc., Houston, Tex, a corporation ofTexas Filed Apr. 6, 1956, Ser. No. 576,696

7 Claims. (Ci. 251--2) This invention relates to control of wellpressure while a well is being drilled, and more particularly to a blowout preventer which will seal in the well when the blowout preventerbore is empty as well as when a length of tubing or the kelly of a drillstring is in the bore without storage of excessive stress energy in theram.

Universal type of rams for use in blowout preventers to seal an openbore or to seal about a section of tubing or the kelly of a drill stringrequire storage of a large amount of strain energy in distorting the rampacking to provide a seal. The amount of strain energy necessarilystored in deforming the packing is so large that manual operation isalmost completely impractical.

It has recently been proposed that a universal ram be provided by aplurality of ram segments movable longitudinally relative to each otherin combination with an equalizer for equalizing the pressure on theseveral ram segments While permitting them to move relative to eachother and assume the contour of an object within the blowout preventerbore.

It is an object of this invention to provide a simple in expensiveequalizer for use with the multi-segment type of universal ram.

Another object is to provide an equalizer for use with a multi-segmentram of the universal type which is mechanical but acts in the manner ofa fluid equalizer to hydraulically apply force equally to the severalram segments while permitting them to assume the contour of an object inthe blowout preventer bore.

Other objects, features and advantages of the invention will be apparentfrom the specification, drawings and claims.

In the drawings, wherein like reference numerals indicate like parts andwherein there is shown by way of illustration two embodiments of thisinvention:

Fig. 1 is a view partly in elevation and partly in vertical crosssection through a blowout preventer constructed in accordance with thisinvention;

Fig. 2 is a view in vertical cross section on an enlarged scale throughthe ram and back stop of the blowout preventer of Fig. l with one of theram segments shown in elevation;

Fig. 3 is a sectional View along the lines 3-3 of Fig. 2;

Fig. 4 is a sectional view along the lines 44 of Fig. 2 with the ramretracted and the segments positioned to give a ram front contoured tothe blowout preventer bore as shown;

Fig. 5 is a View similar to Fig. 4 showing the ram segments in sealingposition about a pipe in the blockout preventer bore.

Fig. 6 is a view similar to Fig. 4 illustrating a modified form ofequalizer; and

Fig. 7 is a fragmentary sectional view along the lines 7--7 of Fig. 6.

The blowout preventer indicated generally at 10 has a body 11 of more orless conventional form adapted to be flanged to a Wellhead in theconventional manner.

2341598 Patented Aug. 2, 1960 Rams, one of which is indicated generallyat 12, are reciprocated in the body by a force transmitting mechanismindicated generally at 13 to move the rams into and out of engagementwith each other or a drill string in the blowout preventer bore 14.

The power transmission mechanism may be operated by hand wheel 15 or itmay be operated by power as is well known to those skilled in the art.The power transmission shaft 16 is journaled for rotation in the body byjournal 17 which is held against reciprocation by a stop ring 18 and ashoulder 19 in the body. A suitable packing arrangement indicatedgenerally at 21 seals about shaft 16.

It has been proposed that the segmented type of ram be used as asecondary ram in the nature of ram front packing as illustrated in thespecification of M. R. Jones, Serial No. 576,637 filed on even dateherewith, now Patent No. 2,855,172, granted Oct. 7, 1958 or as a ram inwhich the segments provide the entire seal for the ram. The latter formof ram is illustrated in the drawings but it will be understood thatthis invention may be used with either form of ram. Where the ramsegments form the entire seal, they are preferably mounted on a carrier22 which is reciprocated by the shaft 16 as by the threaded connection23 between the shaft and carrier to move the carrier in ram bore 20toward and away from the central blowout preventer bore 14. The carrieris provided with an upstanding laterally extending flange part 24 whichextends completely across the top of the carrier and acts as a pusher toreciprocate the ram segments with movement of carrier 22.

Each of the ram segments is formed with a one-piece rigid body 25provided with resilent material 26 at the nose of the ram and along atleast one side face of the ram as well as at the top of the ram at apoint spaced from the nose as indicated at 27. Preferably the sealmaterial 26 covers both side faces of the ram segment as indicated at 28and 29 of Fig. 3. It is further preferred that the rigid body 25 beformed with grooves 31 and 32 in its opposite side faces, with a groove33 in its nose and a groove 34 in the top of the body 25 allintercommunicating with each other and having the seal material 26bonded therein. The exterior surface of the seal material is flush withthe adjacent surfaces of the body except at the nose where it bulgesoutwardly to provide material to contact an object in the blowoutpreventer bore.

The opening and closing force for the ram segments is transmitted fromcarrier 22 through pusher 24 to the several ram segments through amechanical equalizer which functions in a hydraulic manner. Each of theram segment bodies 25 is provided with a notch 35 in its undersurfacewhich extends laterally through the body and is adapted to receivepusher 24 with the distance between the side walls of notch 35beingconsiderably greater than the width dimension of the pusher 24 toprovide spaces between the ram segments and pusher 24 on both sides ofpusher 24. When the rams are inserted in the ram bores these spaces arecompletely enclosed by the wall of the ram bore, the carrier 22, pusher24, and the flexible walls formed by the ram segments 25.

The enclosures so provided contain the mechanical equalizers forreciprocating the ram segments. The equalizer comprises a plurality ofsmooth wall elements which will move over each other in horizontalplanes. Preferably these equalizer spaces are lined. with resilientflexible wall envelopes 36 and 37. However, it will be understood thatsuch envelopes need not be resilient as long as they are flexible. Eachof the envelopes 36 and 37 has a wall in force transmitting relationshipwith each ram segment and is filled with smooth wall elements throughwhich a force may be applied from pusher 2 4 to: the ram segment. In oneform of the invention, these elements are provided by granular material,preferably small steel balls or like members which will move over eachother in the manner of a fluid to change their position when resistanceto movement of the ram segments by pusher 24 is in unequal amounts as byone or more of the ramsegments coming into abutment with an object inthe. blowout preventer bore. In other words, the action is hydraulic innature. The mechanical equalizer will provide a substantially equalforce on the several ram segments as the ram moves out into the blowoutpreventer bore while permitting the segments to assume the contour of anobject in the blowout prevent'er bore. By Filling is meanttosubstantially fill that portion of the enclosures necessary forfunction ofthe equalizer. Preferably, the enclosures are no larger thannecessary to perform this function. However, they could be larger andfilled with equalizer elements from a number necessary for the equalizerto function, to a number necessary to completely fill the enclosures. Byway of example reference is made to Figs. 4 and 5. Fig. 4 illustratesthe retracted position of the ram segments. Fig. illustrates theposition of the ram segments when they are sealing about a tubing in theblowout preventer bore. In moving from the Fig. 4- to the Fig. 5position, the ram segments are permitted to reciprocate relative to eachother as they come into contact with anobject in the central bore suchas tubing 39. Very little force is exerted on the ram segments inengagement with the tubing until after all of the ram segments have beenextended to strike either the tubing or the opposing ram. When all ofthe ram segments are held against further forward movement, pressureexerted through the granular material 38 in envelopes 37 will be exertedsubstantially equally on the several ram segments to force them intosealing engagement with the opposing ram and with the tubing in thecentral bore. As this pressure increases, the bulge of seal material 26in the nose of each ram segment causes the seal material to flowrearwardly along each ram seg ment and press against an adjacent segmentso that a seal will be formed between adjacent ram segments. The sealmaterial exposed at the top of each ram seg= ment in groove 34 is firmlypressed against the ceiling of the ram bore 20. The equalizer ispreferably incontact with seal material 26 and compresses it to assistin providing the desired seals. A seal is thus made between a ram andthe roof of a ram bore and between adjacent hams. The ram segment at thesides of the ram likewise engage the side walls of ram bore and sealtherewith to form a complete seal in the conventional manner.

On opening of the ram bore, the pusher 24 exerts a force on envelope 36which is transmitted through granular material 38 to the several ramsegments to cause them to move rearwardly in ram bore 20.

To reduce the necessary throw of the rams, it is desired to. have theram segments conform to the central bore 14 when retracted. For thispurpose a stop 40' in the ram bore is provided in a position to engagethe ram segments as they are withdrawn. Stop 40 has a curved abutmentface 41 against which the several ram segments abut when they are in aretracted position, and due .to the contour of abutment surface 41 areforced to assume the contour of the blowout preventer bore 14.

Referring. to Fig. 6, there is shown a form ofthis invention in whichrollers 42 replace the granular material 38 as a means of transmittingthe opening and closing force to the rams while permitting them to moverelative to one another. The rollers have a length dimension which willsubstantially fill the vertical distance betweenthe body of the ramsegments and the platform ontop of. carrier. 22. Thespacewithinenvelopes 36 and 37-is completely filled withthese-rollers so that theycannot. tilt from. their vertical axes. As these. rollers are circularin a plane perpendicular to the blowout preventer bore 14 they will moverelative to each other in transmitting a reciprocating force to thesegments as the segments change their relative position. The use ofrollers 42 will permit reciprocation of the ram segments without thereciprocating force tending to lift the ram segments vertically off thecarrier 22 as will be present in the form shown in Fig. 1- through 4.

While the flexible wall envelopes are preferred with either illustnated'form, it will be appreciated that they may be omitted where the size ofthe equalizing elements is such that the elements cannot force their wayinto cracks between the several elements of the enclosure. The flexiblewall envelopes contain the equalizing elements when the rams are out ofthe ram bores and therefore simplifying assembly procedure, but thisfunction might be performed in other ways.

From the above, it will be seen that the objects of this invention havebeen attained. There has been provided a simple inexpensive mechanicalequalizer for a multi-segment ram which will equalize the pressure onthe several segments while permitting themto move relative to eachother. While the equalizer works in a hydraulic manner, it is mechanicalin nature and lends itself to simple fabrication and assembly. it doesnot employ a liquid which might leak out and. render the-raminoperative.

This inventionmay be utilized with a rotatable blowout preventer asshown in my application for Blowout Preventer Serial No. 576,629 filedon even dateherewith, now Patent No. 2,877,977, granted March 1-7, 1959,or as ram front packing as shown in the application of Marv-in R. Jonesidentified herein above.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense;

I claim:

1. A blowout preventer comprising; a housing; a central bore through thehousing to be closed; a plurality of transverse ram bores radiating fromthe central bore; a ram in each ram bore including a plurality of ramsegments arranged side-by-side across the ram and individuallyreciprocal toward and away from the central bore; said ram segmentsforming a pair of flexible walls, means sealing between the ramsegments, and between the ram and ram bore, and between the ram segmentsand an object in the central bore when the segments are forced againstsaid object to seal off the central bore, and sealing ram to ram whenthe central bore is empty and the rams are forced together; and meansforreciprocating each ram segment including a force applying means, and aplurality of smooth Wall solid members having a circular wall in atleast the plane perpendicular to the axis of the central bore fillingspaces formed between the force applying means and each of thcflexiblewalls; said members in one of said spaces transmitting a closing forceto the ramsegments whilepermitting themto move relative ot each otherand the ram fronts to abut when the central here is empty or to assumethe contour of an object in the central bore; andsaidmembers in tieother of said spaces transmitting anopeningforce to the ram segmentswhile permitting them toassume thecontour of the blowout preventer bore.

2. A ram for a blowout preventer comprising a plurality of ram segmentsarranged side-by-side across the ram and having a side wall and nosesection of resilient sealing material for sealing between adjacent ramsegments, and means including a force applying means and a pair ofenvelopes filled with substantially spherical solid particles fordistributing an opening and a closing pressure on the ram substantiallyequally to the ram segments, each envelope having a flexible wall inengagement with a ram segment and another wall in engage ment with theforce applying means, one of said envelopes transmitting a closingpressure to the ram segments while permitting them to movelongitudinally relative to each other and the other envelopetransmitting an opening pressure to each ram segment while permittingthe segments to move longitudinally relative to each other.

3. A ram for a blowout preventer comprising, a carrier, an upstandingpusher attached to the carrier and extending transversely across thecarrier, two envelopes filled With substantially spherical solidparticles arranged one on each side of said pusher and extending thewidth of the carrier, a plurality of ram segments notched to receivesaid pusher and envelopes, said segments supported on the carrier witheach envelope having a wall in force transmitting relationship with thesegments to move the segments and another wall in force transmittingrelationship with the pusher longitudinally upon movement of the pusher,each segment having a side wall and nose section of resilient sealingmaterial for sealing between adjacent ram segments.

4. A blowout preventer comprising; a housing; a central bore through thehousing to be closed; a plurality of transverse ram bores radiating fromthe central bore; a ram in each ram bore including a carrier operablyconnected to the exterior of the blowout preventer through a powertransmission means; an upstanding pusher extending across the width ofthe carrier; said ram also including a plurality of ram segmentsarranged side-byside and individually reciprocable toward and away fromthe central bore and having grooves extending laterally thereacross;said pusher received within said grooves to form spaces at the front andrear of the pusher; envelopes lining each of said spaces and filled witha plurality of smooth wall solid members having a circular wall in atleast the plane perpendicular to the axis of the central bore; one ofsaid envelopes having a flexible wall in abutment with the front of thepusher and the other of said envelopes having a flexible wall inabutment with the rear of the pusher; and means sealing between the ramsegments, and between the ram and ram bore, and between the ram segmentsand an object in the central bore when the segments are forced againstsaid object, and sealing ram to ram when the central bore is empty andthe rams are forced together.

5. A blowout preventer comprising; a housing; a central bore through thehousing to be closed; a plurality of transverse ram bores radiating fromthe central bore; a ram in each ram bore including a carrier operablyconnected to the exterior of the blowout preventer through a powertransmission means; an upstanding pusher extending across the width ofthe carrier; said ram also including a plurality of ram segmentsarranged side-by-side and individually reciprocable toward and away fromthe central bore and having grooves extending laterally thereacross;said pusher received within said grooves to form spaces at the front andrear of the pusher; a plurality of smooth wall solid members fillingsaid spaces and having a circular wall in at least the planeperpendicular to the axis of the central bore; and means sealing betweenthe ram segments, and between the ram and ram bore, and between the ramsegments and an object in the central bore when the segments are forcedagainst said object, and sealing ram to ram when the central bore isempty and the rams are forced together.

6. A ram for a blowout preventer comprising; a carrier; an upstandingpusher on the carrier and extending transversely across the carrier; aplurality of ram segments notched to receive said pusher and formenclosures at the front and rear of the pusher; and a plurality ofsubstantially spherical solid particles filling each of said enclosuresto move the segments longitudinally upon movement of the pusher; eachsegment having a side wall and nose section of resilient sealingmaterial for sealing between adjacent ram segments.

7. A ram for a blowout preventer comprising; a carrier; an upstandingpusher on the carrier and extending transversely across the carrier; aplurality of ram segments notched to receive said pusher and form spacesat the front and rear of the pusher; each segment having a side wall andnose section of resilient material for sealing between adjacent ramsegments; and a plurality of cylindrical rollers arranged with theirrotational axes parallel to the plane of the side walls of the segmentsand filling said spaces to move the segments longitudinally uponmovement of the pusher.

References Cited in the file of this patent UNITED STATES PATENTS1,586,923 Townsend June 1, 1926 2,194,258 Allen Mar. 19, 1940 2,268,262Miller Dec. 30, 1941 2,318,882 Nevill May 11, 1943 2,357,867 Babbitt eta1 Sept. 12, 1944 2,658,415 Barowsky Nov. 10, 1953 2,746,710 Jones May22, 1956 2,754,708 Peterson July 17, 1956 FOREIGN PATENTS 76,279 AustriaApr. 25, 1919

